Corn Flakes (as in the cereal) are a processed food product that contains corn. Flaked maize (or any grain for that matter) is the raw grain that has been passed through rollers at a high temp. The two products do not even resemble each other. Flaked maize resembles oatmeal if anything.

There is no such thing as non gelatinized flaked maize. The rolling of the grain creates friction and heat, thus gelatizining it. The point of buying flaked grains is that you don't have to do a special mash to gelatinize the starches.

Grits are raw corn, but you have to cook them before adding to the mash.

What about corn meal vs grits? And what about grits vs instant grits? Or even corn starch for that matter. And while I'm at it, what about polenta? Isn't that just another name for grits but ground finer?
No time to order flaked corn before a brew day and want to use a few lbs flaked corn but don't have any.

Another question similar in nature. In Mexican cooking, to make corn tortillas, they boil briefly, then soak whole corn kernels in water treated with "lime" or slaked lime, which I believe is calcium hydroxide, a medium strength base/alkali. This raises the pH of the water and this process is called nixtamalization I believe. Then the corn is rubbed after it has cooled to remove the outer husk or seed coat whatever it's called. The bare kernels are then ground into paste mixed with water salt and sometimes lard to make into corn tortillas. I have made these before and is a lot of work but only option for fresh corn tortillas. There is a ready to make flour option available as well that is basically the same but lacks the fresh taste and flavor.

How do these corn products compare with the others I mentioned initially? I would think they would be gelatinized from boiling. Not sure how the nixtamalization alters the suitability in brewing. I think it's supposed to help liberate proteins and amino acids in the corn kernels for digestion.

Was thinking which would be best sub and if necessary to adjust amounts. Does 1 lb flaked corn vs 1 pound of grits for instance give same potential SG points to mash?
I do understand concept of gelatinizing the cereal where needed. Is this needed for instant grits or just regular grits?
I would also imagine some rice hulls would be helpful when using grits in the mash.